X-Ray film-holding device with convex cushion members

Abstract

Swingable front and back plates are supported by a hinge. Cushion members are pasted individually on the inner surfaces of the front and back plates. The cushion members individually have two-dimensional curved surfaces with the same radius of curvature, and are arranged so that the directions of curvature of their curved surfaces cross substantially at right angles. Intensifying screens curved to match the surfaces of the cushion members are pasted thereon. An X-ray film is sandwiched between the intensifying screens, and the front and back plates are joined together. Thereupon, the region of each cushion member, pressing the X-ray film through its corresponding intensifying screens, extends gradually, moving its center from the hinge side to the free-end side. When the front and back plates are joined together, the X-ray film receives a maximum pressing force from the center of each cushion member. The pressing force decreases with radial distance from the center.

What is claimed is: 
     
       1. An X-ray film-holding device for holding an X-ray film, comprising: a front plate and a back plate permeable to X-rays;   supporting means for supporting the front and back plates so that the two plates can be fixed in overlapping relation;   cushion members on the front and back plate sides fixed to opposite faces of the front and back plates, said front- and back-plate-side cushion members having front- and back-plate-side convex surfaces curved in first and second directions, and arranged so that the first and second directions cross each other; and   intensifying screens on the front and back plate sides fixed to and curved along the front- and back-plate-side convex surfaces,   said X-ray film being held between the front- and back-plate-side intensifying screens by the elastic force of the front- and back-plate-side cushion members.   
     
     
       2. The X-ray film-holding device, according to claim 1, wherein said front- and back-plate-side convex surfaces are each curved along the circumference of a circle. 
     
     
       3. The X-ray film-holding device, according to claim 2, wherein said front- and back-plate-side convex surfaces have the same radius of curvature. 
     
     
       4. The X-ray film-holding device, according to claim 3, wherein said front- and back-plate-side cushion members are formed of urethane foam. 
     
     
       5. The X-ray film-holding device, according to claim 4, wherein said X-ray film measures ten inches by twelve, and the radius of curvature of said front- and back-plate-side convex surfaces ranges from 3,500 mm to 4,500 mm. 
     
     
       6. The X-ray film-holding device, according to claim 1, wherein said supporting means includes a swing hinge supporting the front and back plates, and lock means provided on the opposite sides of the front and back plates to the hinge and adapted to fix the front and back plates in closed relation. 
     
     
       7. The X-ray film-holding device, according to claim 6, wherein said X-ray film-holding device is applied to a cassette. 
     
     
       8. The X-ray film-holding device, according to claim 1, wherein said supporting means includes a swing hinge supporting the front and back plates, and an elastic member for urging one of the front and back plates toward the other. 
     
     
       9. The X-ray film-holding device, according to claim 8, wherein said X-ray film-holding device is applied to a fastening device of a cassetteless-type spot-shot apparatus.